The Supreme Court declined a petition by the Redskins yesterday to hear the issue of whether their exclusive, 30-year lease at RFK Stadium is immune from the antitrust laws because a government body created by Congress, the D.C. Armory Board, was a party to the contract.

The suit against the Redskins by Norman F. Hecht now goes back to the U.S. District Court for another trial. In a case that dates from 1968, Hecht contends that he would have obtained an American Football League franchise to play in Washington if he could have gotten permission to play in the stadium.

The Redskins have insisted that Hecht was not assured of a franchise in the league that since has merged with the National Football League.

It was the second time the Redskins were unsuccessful in trying to get the Supreme Court to look into the application of the antitrust laws.

In 1969, the U.S. District Court here ruled that the antitrust laws did apply, but the Court of Appeals overturned that decision. The Redskins asked the Supreme Court to rule on that aspect of the case, but it declined.

In 1975, in a trial in District Court, a jury ruled in favor of the Redskins. The Court of Appeals overturned that decision in 1977.

In January 1978, the Redskins again petitioned the Supreme Court to hear the antitrust issue and that brought yesterday's refusal.

Now that it has been established that the antitrust laws apply, the trust of the Redskins' defense in U.S. District Court is expected to be based on testimony by former American Football League officials and club owners that Hecht's group was not in line for a franchise.

Hecht is seeking damages on the basis of what the value of an AFL franchise might have been had his team been able to play in RFK Stadium.

Associated with Hecht in the litigation are Harry Kagan and Marc A. Miller.

The National Football League originally also was a defendant in the case, but was dropped by Hecht shortly before the trial in 1975.

Hecht said in a response to the Redskins' most recent petition to the Supreme Court that the Armory Board had cited the exclusive stadium lease to him when he sought to rent the facility.

But, he said, the Armory Board stated it was desirous of additional revenue from the stadium and would be "happy" to consider any acceptable and legal arrangements made with the Redskins.